A tech note on the difference between 79-85 & 86+ Toyota 8" Ring & Pinions. Most others have it all wrong by calling it a "4 cylinder" or "v6" 8".
http://www.nitro-gear.com/articles/

 

Also the difference in pinion offset on the 3rd member casting for toyota 8" with OEM 4.88 ratio. IF your vehicle has OEM 4.88, you must change the 3rd member case in order to re-gear. Nitro P/N:
TOY35031 OR TOY35031-V6

 

If you guys have any questions about diffs we would be more then happy to help you out, you can either give us a call at 509 888 2953 or shoot us an email to info@justdifferentials.com.

 

Nice!!!!

 

The difference is also refered to as SPH(Short Pinion Head) vs. LPH(Long Pinion Head). I've been helping to popularize the use of these terms when refering to pre-86 and 86+ R&Ps for some time now, as they describe this phenomenon quite well.

Here's the post from '03 on Pirate:
There's no such thing as "4cyl" and "V6" R&P

 

So Its not called a 4cyl....?

 

So can I pull a complete 3rd out of my 4 cylinder, and stick it in my V6 truck.

 

Yes. The difference between a "4cyl" or a "v6" type Toyota 8" is the 3rd member cast ribbing and bearing bores, and bearing sizes. They fit in the axle housing same either way. In fact we build most of our 8" complete 3rd members into the "4cyl" type housings as it ends up costing much less, but still uses the same ring & pinion and carrier as the latest greatest version of the 8". In the old days if you were comparing a stock 1983 4 cyl diff to a stock "v6" diff there would be a decent increase in strength. Since all the later, better parts can be installed in the old type diffs, there is little benefit to upgrade to the newer type.